Should you buy big floorstanding speakers for your home theater system, or more compact bookshelf speakers? Michael Miller walks you through the different types of speakers available, pointing out the pros and cons of each.

Your home theater system consists of many parts, from the audio/video
receiver to the big-screen television to the DVD player and cable/satellite box.
But of all these components, the ones that most affect the sound you hear are
the speakersall 5.1 of them!

Speaker Basics

Basic speaker technology has remained essentially unchanged for almost fifty
years. The only difference is the number of speakers in your system. Fifty years
ago, a "hi-fi" setup consisted of onecount 'em,
onespeaker. Then came the advent of stereophonic sound, and that one
speaker became tworight and left. Today, to meet the requirements of
surround sound movie soundtracks, your basic home theater setup needs six
speakers: five (hopefully) identical full-range speakers for three front and two
rear (surround) channels, and a separate powered subwoofer for the low frequency
effects (deep bass) channel.

Each of the five full-range speakers in your system consists of a box-like
enclosure and one or more individual speaker elements, called
drivers:

A one-way speaker, like that found in many smaller "satellite"
speakers, has a single driver.

Two-way speaker systems consist of two drivers: a larger one to reproduce
bass and midrange frequencies, and a smaller one to reproduce the higher
frequencies.

Three-way speaker systems consist of three drivers: large for the bass,
midsize for the midrange, and small for the highs.

In a two- or three-way speaker system, the largest speaker (the one that
delivers the bass) is called the woofer. The smaller one (the one that
delivers the highs) is called the tweeter. In three-way systems, the
driver in the middle is called, rather unimaginatively, the midrange. The
single audio signal sent to the speaker cabinet is divided among the two or
three speakers by means of a passive crossover circuit, which splits the
sound according to frequency range.

Some larger speakers include more than three drivers. In fact, some tallish
floorstanding speakers (such as the Polk
Audio RTi12) incorporate multiple drivers of the same size. The thinking
here is that multiple drivers deliver cleaner sound, at louder sound levels.
(More speakers move more air, which makes for louder sound.) Or, depending on
the configuration, several smaller woofers can be employed to do the job of
a single larger woofer.

Some speakers incorporate a built-in powered subwoofer, and are thus
classified as four-way speakers. A built-in subwoofer eliminates the need for a
separate subwoofer elsewhere in your room, and thus results in a cleaner
setup.

Speaker performance is measured in terms of frequency response. The
best tweeters deliver frequencies up to or even exceeding 20 KHz. A good woofer
delivers frequencies down to 40 Hz or lower. The better the speaker system, the
cleaner the sound. Note, however, that high-quality sound is not necessarily
dependent on a particular type of speaker system. A good two-way system can
deliver better sound than a cheap three-way system. And you can't determine
how a speaker sounds by its size; many smallish systems sound better than
speakers with massive woofers. (However, you can somewhat reliably relate
speaker quality to price; more expensive speakers do tend to sound
better!)

While we're talking about size, let's examine the two most common
types of speaker systemsthe larger floorstanding systems and the smaller
bookshelf speakers.